A magnetically levitated (MAGLEV) vehicle may utilize iron core superconducting magnets to achieve vehicle levitation. The magnet iron core may be C-shaped with a superconducting coil on each leg (or a single superconducting coil on the bight of the core. When the superconducting magnet is energized, each leg of the C-shaped core is attracted to an iron rail that is attached to a MAGLEV track. If the superconducting magnet is designed to run in a persistent current mode, the magnet will maintain its electrical current at a given value for an indefinite period of time. A superconducting persistent magnet must be shielded from any fast flux perturbations. Otherwise, these flux perturbations could generate excessive heating in the magnet conductor and its structure and thus might degrade its persistent electrical current quality--or in extreme cases might cause the superconducting magnet to change to the normal resistive state. On the other hand, if the magnet is operated in a DC mode, even then it must be protected from rapid flux perturbations. These flux perturbations could be caused by electrically generated harmonics in the linear traction windings embedded within the rail of a MAGLEV vehicle, or by movement of the C-shaped core with respect to the rail in a direction perpendicular to the rail length.